Fig. 2. Normal cleavage pattern of the O/P lineage. (A) Image of the o (red) and p (green) bandlets in the germinal band of a stage 8 embryo. Ventral is towards the left, and anterior towards the top. Nuclei are stained with Hoechst 33258, and appear blue. (B) Hoechst staining shows the shape and location of the nucleus of each individual cell. One o primary blast cell is undergoing mitosis (red arrowhead), and the more anterior (i.e. older) o blast cell clones consist of the larger o.a daughter cell and the smaller o.p daughter cell (arrows). Further anterior, an o.a cell has divided into two cells, o.aa and o.ap. The most posterior cells in the p bandlet are primary blast cells. Anterior to the p primary blast cells, the older p blast cell clones consist of paired daughter cells p.a and p.p. A p.a cell undergoing mitosis is labeled with a yellow arrowhead. Scale bar: 10 µm.